What does rainstorm cp mean?

This sentence refers to the CP names of Quan Shunrong and Li Zhixun, members of the Korean men's singing group SEVENTEEN.

Quan Shunrong and Li Zhixun's stage names are Hoshi and Woozi, respectively. Their initials are H and W, and they are combined into How, which is called "Heavy Rain" by fans according to homophonic.

The emotional trend of "heavy rain" is complicated, and the relationship between them can be described by words such as tenderness, mutual appreciation and mutual love.